Mechanism for automatically stopping internal combustion engines



r March 3, 1970 D. P. DAT' I ILO 3,498,232

MECHANISM FOR AUTOMATICALLY STOPPING INTERNAL COMBUSTION ENGINES Filed Dec.z1. 1967 DONALD F2 DATTI LO ATTORNEY United States Patent 3,498,282 MECHANISM FOR AUTOMATICALLY STOPPING INTERNAL COMBUSTION ENGINES Donald P. Dattilo, 2395 Tyler Lane, Louisville, Ky. 40205 Filed Dec. 21, 1967, Ser. No. 692,554 Int. Cl. F02p 1/00, 7/00, 11/00 US. Cl. 123-198 10 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to a mechanism for automatically stopping internal combustion engines which include a magneto as part of the conventional ignition system thereof. The mechanism includes a conductive arm connected to a grounded housing of the magneto and a nonconductive arm carrying a conductive contact which is normally biased toward the conductive arm. A conductor spanning the flywheel bell housing area normally maintains the conductive arm and the contact in noncontacting relationship. However, upon the accidental fragmentation of the conventional clutch and/or transmission housings causing the severance of the conductor, the contact of the nonconductive arm is brought into contact with the conductive arm under the influence of a spring to ground the ignition system and automatically stop the automobile engine.

The National Hot Rod Association rules of 1967 provide that Magneto wiring must either be routed outside the frame rail or enclosed in a 16-inch length of Aa-inch minimum wall thickness steel tubing when routed through the flywheel bell housing area. This restriction can be found in the 1967 oflicial Drag Rules of the latter-noted association, and the purpose thereof is to prevent the wiring from being severed by fragments of the clutch, pressure plate, and/or flywheel or the housings thereof when these components tear apart under the stresses which are encountered in, for example, competitive drag racing. If the magneto wiring is severed, it is virtually impossible within the realm of conventional systems to kill or stop the engine, except for positive action on-off switches which do not, of course, automatically stop the engine under emergency conditions and will not under any conditions stop the engine if the wire from the magneto to the kill switch is severed. Furthermore, the rules of the National Hot Rod Association specifically prohibit kill-button type switches because they are in and of themselves incapable of stopping an engine if, as noted heretofore, the magneto wiring passing through the flywheel bell housing area is severed by clutch, transmission, etc. fragments.

Therefore, in accordance with the foregoing it is a primary object of this invention to provide a novel mechanism for automatically stopping internal combustion engines of the type which include a magneto as the part of the ignition system thereof by grounding the engine, preferably through the normally grounded housing of the magneto, the mechanism including a conductive arm connected to the grounded housing of the magneto, and a nonconductive arm normally biased by spring means toward the conductive arm, the nonconductive arm carrying a conductive contact which is normally held in nonconductive spaced relationship to the conductive arm by an electrical conductor disposed between the contact and a fire wall of the automobile frame whereby upon the severance of the conductor by fragments of the pressure plate, clutch, transmission, etc. the contact carried by the nonconductive arm is brought into engagement with the conductive arm and the ignition system is thereby grounded by a conductor connected between the magneto 3,498,282 Patented Mar. 3, 1970 ice housing and the contact carried by the nonconductive arm.

A further object of this invention is to provide a novel mechanism of the type aforesaid wherein a strap-like conductive element secures the conductive arm to the magneto housing, and a torsion or equivalent spring is secured between the arms to normally biasingly urge the same toward each other.

With the above and other objects in view that will.

hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawings.

In the drawing:

FIGURE 1 is a fragmentary schematic side view of an engine and steering assembly of an automobile which includes a magneto as part of its ignition system, and illustrates the mechanism of this invention in its installed condition.

FIGURE 2 is a perspective view of the mechanism of FIGURE 1, and illustrates a strap-like member for connecting a conductive arm of the mechanism to the magneto housing and a nonconductive arm carrying a conductive contact.

FIGURE 3 is a fragmentary side elevational view partly in section of the mechanism of FIGURES 1 and 2, and in solid outline illustrates the arm in the normal installed position thereof and in phantom outline illustrates the arms in a second position at which the ignition system is grounded through the housing of the magneto.

FIGURE 4 is a sectional view taken generally along line 44 of FIGURE 3, and more clearly illustrates a torsion spring for normally urging the arms toward each other.

Referring first to FIGURE 1 of the drawing, a mechanism constructed in accordance with this invention is generally designated by the reference numreal 10, and is illustrated as being secured to a magneto 11 of an automobile engine 12. The engine 12 includes a clutch and pressure plate (not shown) housed beneath a scatter shield 13 as well as a transmission and its housing 14 which is also partially housed beneath the shield 13. The purpose of the scatter shield 13 is to prevent fragments of the clutch, pressure plate and/or transmission in their housings from flying into the flywheel bell housing area and severing conventional magneto wiring of the type heretofore described. That is, in conventional systems an electrical conductor 15 is normally either routed outside the frame rail of the automobile or is enclosed in steel tubing when passing through the flywheel bell housing area, i.e., the area between a fire wall 16 and the engine 12. If in conventional systems the conductor 15 were severed by fragments of the clutch, transmission, etc., the ignition system could not be automatically grounded or killed and it is to this end that the mechanism 10 has been designed.

The mechanism 10 includes a pair of arms 17, 18 pivotally connected to each other by a rivet 20, and normally biasingly urged toward each other by a torsion spring 21 having ends 22, 23 (FIGURE 4) received in openings (unnumbered) of the arms 18, 17, respectively. The arm 17 is generally U-shaped in transverse section and includes a pair of legs 24, 25 and a bight portion 26. The arm 17 is constructed from conductive material and forms one of a pair of conductive elements or contacts of the mechanism 10, as will appear more clearly hereafter. The legs 24, 25 of the arm 17 are provided with respective slots 27, 28 through which passes a strap-like connector 30 which may be, for example, a conventional hose clamp. The strap-like connector 30 is constructed from conductive material and by means of a suitable nut and bolt (unnumbered) it is designed to secure the mechanism to the magneto 11 in the manner readily obvious from FIGURE 1 of the drawing.

The arm 18 of the mechanism 10 carries an electrically conductive element 31 in the form of a headed bolt which includes a threaded end portion 32. In the installed position of the mechanism 10 (FIGURES l and 2) the arm 18 is normally disposed at an angle of approximately 90 degrees to the arm 17 and the contact 31 is maintained in spaced relationship to the conductive arm 17. The arm 18 is maintained in the installed position shown best in FIGURE 1 by the conductor which is secured to the contact 31 by a conventional loop terminal 34. The conductor 15 is passed through an eyelet 35 secured to the fire wall 16, and is also passed through a grommet 36 of insulating material in the fire Wall 16. The conductor 15 is secured to a steering column 37 in a conventional manner and is electrically connected to ground. Due to the connection of the conductor 15 to the column 37, the arm 18 in the installed position of the mechanism 10 is held in the position shown in FIGURE 1 with the contact 31 appreciably spaced from the conductive arm 17 while being biased for swinging movement into contact with the arm 17 by the spring 21.

In the installed position of the mechanism 10 (FIG- URE 1) the contact 31 is also connected to the grounded housing (unnumbered) of the magneto 11 by means of a conductor 40 having loop terminals (unnumbered) at each of the ends thereof. A hex washer 41 and a nut 42 secure one end of the conductor 40 to the contact 31 while the opposite end of the conductor 40 is similarly secured to the conventional threaded ground terminal of the magneto 11 by a hex washer and nut corresponding to the elements 41, 42. It is to be particularly noted that the conductor 40 is looped, as clearly shown in FIGURE 1, to permit the nonconductive arm 18 to swing downwardly in the direction of the unnumbered headed arrow in FIGURE 3 of the drawing upon the severance of the conducotr 15 to bring the contact 31 into electrical contact with the conductive arm 17 The operation of the mechanism 10 is, as was heretofore noted, designed primarily for shutting off or grounding combustion engines which include magnetos in the ignition systems thereof when the normal ignition systems fail for any reason whatever, but particularly when such conventional systems fail as a result of a severance of the magneto wiring in the flywheel bell housing area. To date if the conventional conductor corresponding to the conductor 15 fails or breaks for any reason there is no way for the driver of an automobile to stop the engine 12. However, in accordance with this invention, it will be assumed that the ignition system and engine are operating properly but because of vibration, Wear, stresses, etc., the conductor 15 is severed or broken. In conventional systems, as was heretofore noted, the engine 12 would not be grounded and could not be otherwise stopped. However, in the instant case, the spring 21 rapidly pivots the arm 18 downwardly in the direction of the unnumbered headed arrow in FIGURE 3 to bring the contact 31 into contact with the bight portion 26 of the conductive arm 17 which, as was heretobefore noted, is electrically conductively connected by the strap-like member 30 to the grounded magneto housing 11. Upon the contact of the contact 31 with the arm 17, the magneto 11 is automatically grounded and the engine 12 is likewise grounded through its ignition system and stopped. This automatic stopping of the engine 12 could not be accomplished if, for example, the mechanism 10 Were eliminated and the conductor 15 were connected directly between the magneto housing and the kill switch 38. In this case, the kill switch 38 is normally in its open position when the automobile is running and when closed the magneto 11 would be grounded only if the conductor 15 were not severed. However, if the conductor 15 were broken, again in the absence of the mechanism 10, the closing of the kill switch 38 would not connect the magneto to ground and the engine could not be stopped. Thus, the mechanism 10 is a foolproof measure to ensure the auotmatic and rapid stopping of all engines whose ignition systems include magnetos when the conductor or wiring 15 is severed for any reason whatever, and particularly when the conductor 15 is severed by the usual wear and tear encountered thereby in the flywheel bell housing area which has heretofore been in no way adequately provided for by any known safeguards, including the encasement of the conductor 15 in steel tubing as provided for by the rules of the National Hot Rod Association.

While preferred forms and arrangement of parts have been shown in illustrating the invention, it is to be clearly understood that various changes in details and arrangement of parts may be made without departing from the spirit and scope of the invention as defined in the appended claimed subject matter.

I claim:

1. A mechanism for stopping an internal combustion engine which includes a magneto as a part of the ignition system thereof having conductor means for grounding the ignition system, said mechanism comprising a pair of electrically conductive contacts, means for electrically conductively connecting one of said contacts to a grounded element of said automotive ignition system, means for electrically insulating the other of the conductive con tacts from said one contact in the installed condition of said mechanism, said conductor means holding said contacts in non-contacting relationship, and means for urging said contacts toward each other whereby upon the severance of said conductor means said urging means brings said contacts together to ground the engine through a conductive element connected between said other conductive contact and said grounded element.

2. The mechanism as defined in claim 1 wherein said grounded element is the housing of said magneto.

3. The mechanism as defined in claim 1 wherein said electrically insulating means is an electrically nonconductive arm carrying said other contact, and said urging means is spring means for normally biasingly urging said nonconductive arm and said other contact toward said one contact.

4. The mechanism as defined in claim 1 wherein the grounded element is a magneto housing, and said connecting means is a strap-like member for exteriorly surroundingly engaging said housing.

5. The mechanism as defined in claim 1 including means for connecting said conductive element to said other contact.

6. The mechanism as defined in claim 3 wherein the grounded element is a magneto housing, said said connecting means is a strap-like member for exteriorly surroundingly engaging said housing.

7. The mechanism as defined in claim 3 including means for connecting said conductive element to said other contact.

8. The mechanism as defined in claim 4 including means for connecting said conductive element to said other contact.

9. In combination with an internal combustion engine which includes a magneto as a part of the ignition system thereof, said magneto having a grounded housing, and an electrical conductor forming a portion of said ignition system being disposed generally between said magneto and an automotive firewall and being thereby susceptible to severance by clutch, and/ or transmission fragments or the like, the improvement comprising a pair of electrically conductive contacts, means for electrically conductivetly connecting one of said contacts to a grounded element of said ignition system, means for electrically insulating the other of the conductive contacts from said one contact means electrically conductively connecting said electrical conductor to said other contact and means for urging said contacts toward each other whereby upon the severance of said electrical conductor which holds said contacts in noncontacting relationship said urging means brings said contacts together to ground the engine through said electrically conductive connecting means and said grounded element.

10. The combination as defined in claim 9 wherein said grounded element is said magneto housing.

References Cited UNITED STATES PATENTS 6 4/1934 Bate 123198 5/1940 Cale 123-198 3/1960 Haworth et a1. 123198 XR 7/ 1966 Desaulniers 123198 3/1967 Amsbury 123198 XR FOREIGN PATENTS 2/ 1941 Germany.

WENDELL E. BURNS, Primary Examiner US. Cl. X.R.

123146.5; ISO-96, 103 

